> Arrest first and ask questions later is a dystopian legal tactic.
It's also the only practical tactic when there's a chance of the targets of an investigation hiding evidence, fleeing, or otherwise hindering that investigation.
None of which was involved in this case. You don’t arrest people for minor traffic violations for example. You detain them to collect relevant information aka pull them over, then let them go.
You're missing the point... it's not possible to tell in advance whether someone should be arrested or not, you have to follow a standard procedure for a lot of reasons, not the least of which is that doing so safeguards everyone's rights.
In the case of traffic violations, the decision to not arrest by default is made far in advance as a matter of policy. When someone at a traffic stop gets arrested, it's not for the traffic violation, it's for another crime they're wanted for, and the standard process for that overrides the traffic stop process.
"arrest" is a vague term. There is a gap between "detaining" someone while investigating the situation, and "jailing" them. Note that if
jails were designer according to "innocent until proven guilty" as legally required, then being jailed temporarily wouldn't be so bad.
It's also the only practical tactic when there's a chance of the targets of an investigation hiding evidence, fleeing, or otherwise hindering that investigation.